Objective pivoting device having crossed swivelling axes

ABSTRACT

The invention relates to an objective pivoting device ( 1 ) for pivoting an objective which is concentrically arranged in said device, about two perpendicular swivelling axes (A-A; M-M) which cross each other at a common apex in the optical axis of the objective. The inventive device comprises pivoting adjustment means ( 20, 21 ) which are respectively provided with a cable drive having three cable sections ( 20 A- 20 C;  21 A- 21 C), the first cable section ( 20 A,  21 A) extending from an adjustment axle coil ( 22 A,  23 A) to the first of the bearing elements ( 15, 40 ), the second section ( 20 B,  21 B) extending from said first bearing element to a second bearing element ( 15, 40 ) which is coaxial in relation to the first, and the third cable section ( 20 C,  21 C) returning from said second bearing element to a second coil ( 22 B,  23 B) of the adjustment axle ( 22 C,  23 C) of the pivoting adjustment means ( 20, 21 ).

The invention is concerned with a pivoting device for pivoting anobjective concentrically arranged therein, about two mutuallyperpendicular swivelling axes that cross each other at a point ofintersection on the optical axis of the objective, wherein the objectiveis held in an objective holder, and the same is supported pivoting inbearings in two degrees of freedom of a spherical surface and thesebearings are disposed on a stationary holding frame on which twopivoting adjustment means are provided, one of which is operativelylinked with meridionally diametrical bearing elements, and the other onewith equatorially diametrical bearing elements of the objective holderin each case, the latter having a compensating degree of freedom.

A pivoting device of this type is known from WO98/47034. The relativelylarge, thin annular gears and toothed segments, which are used aspivoting adjustment means, are very expensive to produce due to the factthat a high degree of precision and good gliding properties arerequired.

Additionally, a pivoting device is known from U.S. Pat. No. 5,502,598 A.The spherical objective holder is supported on its spherical surface.This objective holder incorporates a meridionally oriented toothedsegment drive and, located orthogonal to it, an equatorial toothedsegment drive, the toothed segment of which is located on a sphericalsegment that is pivotable about the shaft of the equatorial drive andthe swivelling axis of which is displaceable in a channel located in ameridional plane in the spherical segment. The driving pinion may beimplemented conically complementary to the toothed segment, and thegearwheel shaft is guided in an equatorial channel on the sphericalsegment. The drive moment of the gearwheel on the toothed segmentproduces, in dependence upon its direction, an outward displacement ofthe spherical segment in the channel in each case, so that no uniquerelationship exists between the meridional and equatorial objectivepivoting movement and the adjustment rotations of the two drives, whichis sufficient for the purpose of an objective panning, but insufficientfor a specific camera objective adjustment.

Additionally, from DE 296 096 U1, a camera adjustment system is known,wherein a cylindrical bearing is provided at the foot of an objectiveframe for pivoting the frame about an axis that crosses the objectiveaxis, and wherein on the supported cylinder section a pivot bearingabout a vertical axis is provided, which intersects with the otherswivelling axis in the optical axis. Because of the large distance ofthe pivot bearings from the optical axis, the bellow adjoining theobjective carrier during major pivoting movements of the same ofteninterferes with the beam path, and additionally the bellow is subjectedto significant mechanical stress due to a kinking that occurs in theprocess. Preventing this oftentimes requires re-adjusting the entirecamera system. These problems are particularly severe with the use ofwide angle objectives.

It is the object of the invention to simplify in its production andimprove in its reliability the above described pivoting device whereinthe support, the operating elements located thereon for adjusting thepivot movement, and the bellow are stationary and essentially only theobjective is pivoted therein.

This object is met in such a way that the compensating degree of freedomof the equatorial bearing elements is provided in each case through apivotability in a bearing element on the holding frame or by adisplaceability in a given meridional plane on the objective holder, andthat the pivoting adjustment means in each case comprise a cable drivewith three cable sections, the first cable section of which is guidedfrom a coil around the adjustment shaft to the first of the bearingelements and the second cable section from this bearing element to asecond bearing element that is coaxial to the former, and the thirdcable section is guided back from it to a second coil around theadjustment shaft of the pivoting adjustment means, and that the twocable sections that act upon one of the bearing elements meet in eachcase in the given bearing element on its associated swivelling axis in apivoting region of a bearing shield of the bearing element and are fixedin each case on the bearing shields in an associated manner at one andthe other end of an equatorial or meridional guide channel, into whichan associated guide deflection roller engages in a guiding manner ineach case.

Advantageous Embodiments are Specified in the Subclaims.

Each cable control is provided with at least one cable tensioning meansand the cable controls are guided around the spherical-segment shapedobjective holder, into which the bearing shields are inserted, by meansof deflection rollers in such a way that they meet with the guidechannels of the bearing shields approximately tangentially in each case.

The two cable controls are disposed above one another or crossing oneanother at a height above the holding frame. The upper and lowerdeflection rollers are mounted in each case on common shafts in such away that two of the deflection roller pairs in each case are mounted ina corner region of the holding frame and an additional roller is mountedbetween the lower rollers, at least one of which per cable control isloaded with a cable tension spring or provided with a cable tensioningmeans.

The guide deflection rollers are grouped together in each case in anassembly together with two associated obliquely mounted deflectionrollers, so-called leveling rollers, and held in a bearing block. Theshafts of the meridionally oriented guide deflection rollers are fixedon the holding frame, and in a preferred embodiment, to ensure acompensating degree of freedom, the shafts of the equatorial guidedeflection rollers are supported on the holding frame in a manner sothat they can pivot about the equatorial axis A-A. The bearing elementsare protected from twisting relative to the bearing shield in each caseby a guide tappet in the guide channel of the bearing shield.

In an alternate embodiment, the compensation movements are ensured ineach case by a displacement guidance of the bearing shields in themeridional direction on the objective holder.

During a torsional rotation of the shaft of the associated pivotingmeans, the one cable end that is being wound up, pulls on the connectedend of the bearing shield, causing the second cable section that islocated at the other end of the bearing shield to be pulled along, whichis fixed to the bearing shield end of the opposed bearing shield anddeflects the same in the opposite direction, causing the third cablesection that is located at its other bearing shield end to be pulledalong, which is being released from the other adjustment shaft coilregion in each case through the torsional rotation of the adjustmentshaft. During a rotation in the opposite direction the movements arereversed.

Since the bearing shields are inserted into the spherical-segment shapedobjective holder, the same is pivoted in one or the other direction bythe adjustment of the former that is effected by the cable control. Thepivoting movement takes place in the equatorial bearings relative to theholding frame and in the meridional bearings between the bearing shieldsand the objective holder.

The entire assembly of the adjusting elements and bearing elements isheld together in an easy to open manner with a cover frame.

The assemblies and rollers are repetition parts. The cables areunchanged in their lengths, due to the two intersecting locations ineach case on the swivelling axis when the crossed axis is pivoted. Themovements of the two axes are therefore independent from one another anduniquely associated with the adjustment on the given adjustment shaft.

Since two cable ends act upon one bearing element in each case, allbearings are free from lateral forces. The objective holder “floats” inthe cables, which meet in the axes in each case.

Advantageous embodiments are shown in FIGS. 1 through 7.

FIG. 1 shows a view in the perspective with the front cover lifted;

FIG. 2 shows the objective holder in an exploded view;

FIG. 3 shows the holding frame with the adjustment and bearing elements;

FIG. 4 shows a bearing element in an exploded view;

FIG. 5 shows the assembly of the objective holder;

FIG. 6 shows the objective holder being enclosed;

FIG. 7 shows the bellow connection side of the pivoting device.

FIG. 1 shows a frontal view in the perspective of the pivoting device 1with the front cover 10 lifted. In the rear housing 11, a holding frame17 is held, in which the annular objective holder 53 is held with itsspherical surface pivotable about two axes. Two of the bearing shields33, 34, which are located perpendicular to one another with their axes,visibly project with a small section from the front half 54B of theball-socket bearing half. The bearing shields 33, 34 have a commonsurface with the objective holder 53 and are embedded within it.

Disposed on the ball socket bearing 54B is a circuit board 12, whichcarries measuring and control components.

Laterally projecting from the housing 10, 11, are pivoting adjustmentshafts 20, 21, which are actuated by means of the pivoting adjustmentmeans, which effect the pivoting of the objective holder.

FIG. 2 shows the objective holder 53, into which an interchangeableobjective is insertable, which is held axially with a retaining ring 56,which is removably secured with spring-loaded fasteners 58.

The four bearing shields 31-34 form circular sections of the objectiveholder 53. Two opposed ones of the bearing shields 31, 33, are heldoriented with receptacle skids 60, 61 in the objective holder 53 in sucha way that their outer guide channels 35, 37 are oriented perpendicularto a center plane of the objective holder 53. The other two bearingshields 32, 34 are inserted in the objective holder 53 in a manner sothat they can rotate freely.

The center axes A-A, M-M of the opposed bearing shields 31, 33; 32, 34intersect in the optical axis of the objective to be inserted.

FIG. 3 shows the holding frame with the adjusting means that pivot thebearing shields 31-34. For both pivot movements about the axes A-A, M-M,cable control assemblies are provided that are identical in principle.The adjustment shafts 20, 21, for example, are disposed coaxiallyoriented at the bottom or top so that one swivelling axis A-A may beviewed as equatorial and the other axis M-M extends in a meridionalplane through the poles.

The adjustment shafts 20, 21 incorporate two cable coils 22A, 22B; 23A,23B in each case, which are to be wound up or unwound in each case, andare unwound in such a way that the total cable length remains constant.The cable ends exit tangentially and are guided further via rollers 20so that only a negligible change in cable length occurs when the shafts20, 21 are rotated torsionally.

In the corner regions of the holding frame, there is an assembly in eachcase of two double roller holders and a lower offset tension roller 65.The coaxial double rollers 61, 61; 63, 64 hold the two cable systemsapart in different planes; however, the cables alternate in each case intheir plane along the long distance from corner to corner. At least oneof the tension rollers 65 per cable control is loaded with a tensionspring so that tolerances that occur due to temperature changes or agingare compensated for.

The two cable controls each consist of three sections 20A-20C; 21A-21C.The first section 20A, 21A starts at the first cable coil 22A, 23A andleads to a first bearing shield 31, 32, where it ends at the upper endof the guide channel 35, 36. From the lower end of the guide channel,the second cable section 20B, 21B extends to the given opposite bearingshield, 33, 34, where it is fixed at the lower guide channel end. Fromthe upper end of this guide channel, 37, 38, the third cable section20C, 21C extends to the second coil 22B, 23B to the adjustment shaftsection 22C, 23.

In front of the bearing shield 31-34, a guide deflection roller 39 issupported in each case, which is guided with its flanks inside the guidechannel 35-38. The two cable ends that are fixed in the guide channel ineach case overlap there and extend deflected in the channel of thedeflection roller 39 by 90° in each case and from there to two levelingrollers 39A, 39B, that are tangentially in alignment in theircircumferences, which are mounted obliquely such that the two cable endsenter and exit approximately in alignment. In this manner the enteringand exiting cable ends intersect in front of and behind the guidedeflection roller 39 in each case, approximately on the given swivellingaxis A-A, M-M that permeates the bearing.

Two bearing types 15, 40, are provided, one of which are the meridionalbearings 15, wherein the pivoting of the objective holder takes placeabout the shields 31, 33, and the shaft 41 of the guide roller 39 isrotatably supported on the holding frame 17.

The other bearing type 40 permits a pivoting of the objective holderabout the equatorial axis A-A in such a way that the guide roller 39pivots along in a bearing 40.

The two bearing types 15, 40 on the two axes A-A, M-M, convey to theobjective holder the degrees of freedom that it needs for theindependent pivoting movements.

The four deflection assemblies 39, 99A, 39B with the bearing 40 aredesigned essentially identical, as shown by FIG. 4 in an exploded view.

In the two bearing blocks 43, the leveling rollers 39A, 39B are mountedobliquely on shafts 42 locked in grooves. On the two bearing blocks 43,one complementary half-round bearing shell 40A, 40B is located, in whichinner bearing halves 40C, 40D are supported. The bearing shells 40A-40Chave transversal bores in which the guide deflection rollers 39 arerotatably supported on the shaft 41. In the meridional bearing elements15, FIG. 3, the bearing elements 40 are prevented in each case byoverlength shaft ends 41E on the shaft 41 from pivoting into the outerbearing shells 40A, 40B.

The bearing element 40C incorporates a guide tappet that engages in theguide channel of the bearing shield besides the guide deflection roller39.

The two assemblies of the different swivelling axes A-A, M-M thusdiffer, from a structural point of view, only in the type of shaft 41.

FIG. 5 shows the assembly of the objective holder 53 with the bearings15, 40 on the holding frame 17. The objective holder 53 is held in thesebearings and the spherical surface 16, as well as the complementaryspherical casing sections 16A have only a loose fit and are not bearingelements.

FIG. 6 shows the objective holder 53 already mounted into the holdingframe 17 and the mounting screws 18 for it, and also for the assembly ofthe front spherical casing section 16B.

In the figure, in the front corner region of the holding frame 17, onecan see belt tensioning means with the tension roller 65, which isloaded by the tension spring 66 via angle levers 67, the pretension ofwhich is adjustable by means of an adjusting screw 68. Locateddiagonally opposite is an additional cable tensioning means of identicaldesign for the second cable system. The other roller assemblies in thetwo additional corner regions are assembled with only the adjustingscrew without a spring.

The pivoting by means of the cable controls gives the designer greatfreedom with regard to the arrangement of the adjustment shafts 20, 21,which may be placed in any direction. Turning knobs and/or adjustingmotors may be connected to it as well.

For controlling or regulating the adjustment, position transmitters areprovided in the form of magneto-sensoric zero position transmitters inthe region of the bearing shields and incremental transmitters 70, 71 onthe adjustment shafts 20, 21.

The alternate embodiment of the degree of freedom for the compensationmovement is shown in a dot-and-dash pattern on the objective holder 53for the equatorial bearing shield 15, which, like the diametricalbearing shield, is supported accordingly in a guide recess 73 not onlyrotatable but also displaceable on the circumference of the objectiveholder. In that case, no pivot bearings are provided on the holdingframe, thus rendering these assemblies simplified.

FIG. 7 shows the rear of the pivoting device 1 with the connectingprofile for the bellow, the edge of which is to be fixed in an easilyremovable manner with eccentric levers.

The bearing blocks, as described above, are repetition parts, however,this time they are implemented diametrically opposed mirror-invertedrelative to the cable guidance. If the same is now reversed, thedirection of movement of the objective holder relative to the directionof rotation of the adjustment shaft changes.

In the example, one tension spring is provided in each case per cablecontrol, and an adjusting frame without tensioning spring. This permitsa centering of the position of the objective holder in a fixed relationto the support plate with the rigidity of the cable in the pulldirection towards the bearing block on one hand and the elasticity ofthe spring in relation to the adjustment shaft on the other hand. If twosprings are used per cable control, this produces a greater flexibilityfor the position of the objective holder when there is an external forceacting upon it. It offers protection against a tearing of the cable,however, in that case it is recommended that progressively actingsprings be used and/or indicators be mounted on the spring supports thatsignal any impermissible threshold deflections. The threshold signalsfrom the indicators are routed to the circuit board, which is mounted onthe support plate with a connection plug.

A plug connection is also provided on the objective holder towards theobjective, so that characteristics of the objective that are storedelectronically readable or which are readable from it can be supplied tothe electronics on the circuit board.

List of Reference Numerals:

-   A-A; M-M Swivelling Axes-   1 Pivoting Device-   10 Front Cover-   11 Rear Cover-   12 Circuit Board-   15 Bearing Elements-   16 Spherical Surface-   16A, 16B Spherical Casing Segments-   17 Holding frame-   18 Screws-   20, 21 Pivoting Adjustment Means-   20-20C 3 Cable Sections-   21A-21C 3 Cable Sections-   22A, 23A 1^(st) Adjustment Shaft Coil-   22B, 23B 2^(nd) Coil-   22C, 23C Adjustment Shaft Sections-   31-34 Bearing Shields-   35-38 Guide Channel-   39 Guide Deflection Roller-   39A, 39B Leveling Rollers-   40 Bearing Elements-   40A, 40B Bearing Shells-   40C, 40D, Inner Bearing Halves-   41 Shaft for 39-   41E Shaft End Sections-   42 Shafts for 39A, 39B-   43 Bearing Blocks-   44 Guide Tappet-   53 Objective Holder-   54A,B Ball Socket Bearings-   56 Retaining Ring-   58 Fasteners-   60 Deflection Rollers-   61-64 Deflection Rollers-   65 Tension Roller-   66 Tension Spring-   67 Angle Lever-   68 Adjusting Screw-   70,71 Incremental Angle Transmitter-   72 Eccentric Levers-   73 Guide Recess

1. An objective pivoting device (1) for pivoting an objectiveconcentrically arranged therein, about two mutually perpendicular axes(A-A; M-M) that cross at a point of intersection on the optical axis ofthe objective, wherein the objective is held in an objective holder (53)and the same is supported pivoting in bearings (15, 40) in two degreesof freedom of a spherical surface (16) and these bearings (15, 40) aredisposed on a stationary holding frame (17) on which two pivotingadjustment means (20, 21) are provided, one of which is operativelylinked with meridionally diametrical bearing elements (15), and theother one with equatorially diametrical bearing elements (15) of theobjective holder (53) in each case, and wherein the latter have acompensating degree of freedom, characterized in that the compensatingdegree of freedom of the equatorial bearing elements (15) is provided ineach case through a pivotability in a bearing element (40) on theholding frame or by a displaceability in a given meridional plane on theobjective holder (53) and that the pivoting adjustment means (20, 21) ineach case comprise a cable drive with three cable sections (20A-20C;21A-21C), the first cable section (20A; 21A) of which is guided from acoil around the adjustment shaft (22A; 23A) to the first of the bearingelements (15, 40) and the second cable section (20B, 21B) from thisbearing element to a second bearing element (15, 40) that is coaxial tothe former, and the third cable section (20C, 21C) is guided back fromit to a second coil (22B, 23B) around the adjustment shaft (22C, 23C) ofthe pivoting adjustment means (20, 21), and that the two cable sections(20A, 20B; 20B, 20C; 21A, 21B; 21B, 21C) that act upon one of thebearing elements (15, 40) meet in each case in the given bearing elementon its associated swivelling axis (A-M, M-A) in a pivoting region of abearing shield (31-34) of the bearing element and are fixed on thebearing shields (31-34) in each case in an associated manner at one andthe other end of an equatorial or meridional guide channel, into which aguide deflection roller (39) engages in a guiding manner in each case.2. The objective pivoting device of claim 1, characterized in that theguide deflection rollers (39) of the meridional swivelling axis (M-M)are supported on the holding frame (17) only rotatable and the otherguide rollers (39) are supported rotatable and pivotable about theequatorial axis (A-A) in the bearing elements (40), or the associatedbearing shields (32, 34) are held displaceable in the meridionaldirection in guide recesses (74) in the objective holder (53).
 3. Theobjective pivoting device of claim 2, characterized in that the bearingelements (40) consist of outer and inner bearing shells (40A, 40B; 40C,40D) that are fixed with bearing blocks (43) on the holding frame (17)in each case.
 4. The objective pivoting device of claim 3, characterizedin that the inner bearing shells (40C, 40D) incorporate support boresfor supporting a shaft (41) of the guide deflection roller (39).
 5. Theobjective pivoting device of claim 3, characterized in that at least theouter bearing shells (40A, 40B) contains a bore coaxial to inner supportbores, into which one shaft end (41E) of a shaft (41) projects when thebearing elements (40A-40D) are fixed relative to one another.
 6. Theobjective pivoting device of claim 3, characterized in that in the twobearing blocks (43) located away from the respective bearing shield(31-34), one leveling roller (39A, 39B) is disposed in each case slantedtoward the other one and toward the holding frame (17) in such a waythat the cable that is guided over the same and exiting tangentially,meets the guide deflection roller, and tangentially meets the othercable on the given swivelling axis (M-M, A-A).
 7. The objective pivotingdevice of claims 3, characterized in that at least one of the innerbearing shells (40C, 40D) carries a guide tappet (44) that guidinglyengages into a guide channel (35-38).
 8. The objective pivoting deviceof claims 1, characterized in that in each corner region of the holdingframe (17) three deflection rollers (61, 63, 65) are disposed offsetfrom one another and the one in the center is a tension roller (65) thatis supported inside an angle lever (67), which has an adjusting screw(68) acting upon its other side.
 9. The objective pivoting device ofclaim 8, characterized in that in each cable control (20A-20C; 21A-21C)at least one of the adjusting screws (68) acts upon the angle lever (67)via a tension spring (66).
 10. The objective pivoting device of claim 8,characterized in that on the shafts of the stationary deflection rollers(61, 63) an additional deflection roller (62, 64) is supported coaxiallyin each case, over which the given other cable control is guided. 11.The objective pivoting device of claims 1, characterized in that adeflection roller (60) is disposed near the adjustment shaft coil (22B,23B) in each case, in such a way that the deflected cable (20C, 21C)extends tangentially to the adjustment shaft (20, 21).
 12. The objectivepivoting device of claims 1, characterized in that the adjustment shafts(20, 21) carry an incremental angle transmitter (70, 71) in each case,and at least two zero position indicators are directly or indirectlydisposed on the objective holder (53).
 13. The objective pivoting deviceof claims 1, characterized in that the objective holder (53) is heldcentered in the bearing shields (31-34) on the cable controls (20A-20C;21A-21C) and disposed in a loose fit in annular ball socket bearings(54A, 54B), one of which is disposed on the support plate (17).
 14. Theobjective pivoting device of claim 12, characterized in that theincremental angle transducers (70, 71) and zero indicators are connectedto a contact unit, to which a circuit board (12) is connected by meansof contacts, said circuit board (12) being disposed on the holding frame(17) in front of the pivoting adjustment means (20, 21).
 15. Theobjective pivoting device of claim 1, characterized in that the holdingframe (17) is disposed in a rear housing (11), which incorporates abellow connection channel and eccentric levers (72) to fix the bellow.16. The objective pivoting device of claim 15, characterized in that therear housing (11) is covered with a front cover (10) so that the acircuit board (12) and the holding frames (17) with the adjusting andbearing elements (40) are enclosed therein, with the objective holder(53) projecting with its edge regions from a circular opening.
 17. Theobjective pivoting device of claim 1, characterized in that theobjective holder (53) carries at its front, inside an annular channel, aretaining ring (56) that is openable with a spring-loaded fastener (58)to exchange the objective.